全文获取类型
收费全文 | 958篇 |
免费 | 152篇 |
国内免费 | 489篇 |
专业分类
安全科学 | 136篇 |
废物处理 | 143篇 |
环保管理 | 91篇 |
综合类 | 796篇 |
基础理论 | 167篇 |
污染及防治 | 216篇 |
评价与监测 | 39篇 |
社会与环境 | 9篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 9篇 |
2023年 | 18篇 |
2022年 | 26篇 |
2021年 | 43篇 |
2020年 | 45篇 |
2019年 | 41篇 |
2018年 | 43篇 |
2017年 | 35篇 |
2016年 | 58篇 |
2015年 | 74篇 |
2014年 | 78篇 |
2013年 | 118篇 |
2012年 | 107篇 |
2011年 | 114篇 |
2010年 | 61篇 |
2009年 | 72篇 |
2008年 | 50篇 |
2007年 | 94篇 |
2006年 | 98篇 |
2005年 | 76篇 |
2004年 | 62篇 |
2003年 | 44篇 |
2002年 | 42篇 |
2001年 | 32篇 |
2000年 | 41篇 |
1999年 | 27篇 |
1998年 | 20篇 |
1997年 | 12篇 |
1996年 | 11篇 |
1995年 | 13篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有1599条查询结果,搜索用时 828 毫秒
841.
酸性矿井水成分复杂、产量大,是严重的矿山环境问题,也是处理难度大的污废水体。采用超高石灰铝法,通过分别投加Ca O和Na Al O2对实验室配置的模拟酸性矿井水进行处理。实验分析溶液p H值、药剂投药比、初始浓度以及反应温度等因素对氯离子和硫酸根去除率的影响。结果表明,当Cl-的质量浓度为2 500 mg/L,SO2-4质量浓度为1 500 mg/L时,搅拌温度40℃,投加Ca O和Na Al O2的量分别为4.0 g和1.0 g,滴加Na OH调节p H值为10,搅拌15 min,Cl-,SO2-4去除率分别为87.9%,96.0%。 相似文献
842.
固定化优势菌种处理NH3和H2S恶臭气体 总被引:5,自引:0,他引:5
用海藻酸钠作包埋剂固定优势菌种(枯草芽孢杆菌、白曲霉菌、葡萄球菌)处理NH3和H2S。考察了气体流量、NH3和H2S气体浓度、循环液喷淋量对NH3和H2S去除效果的影响。固定化生物滴滤反应器最佳运行条件为:气体流量1.0m3/h、循环液喷淋量8.88L/h、进气H2S质量浓度低于51.85mg/m3、进气NH3质量浓度低于57.21mg/m3。处理NH3和H2S的最大容积负荷分别为634.1g/(m3·d)和699.6g/(m3·d)。处理后出气中的NH3和H2S的质量浓度分别达到GB14554—93《恶臭污染物排放标准》中的一级排放标准和二级排放标准。 相似文献
843.
844.
以锌粉为还原剂进行了聚氯乙烯(PVC)的机械化学还原脱氯(简称脱氯)探索研究,考察了球磨转速、球料比(磨球与试样的质量比)、锌粉与PVC质量比等对脱氯率的影响,并对脱氯产物进行了X射线衍射、红外光谱等分析。实验结果表明,最佳工艺条件为球料比33、球磨转速528r/min、锌粉与PVC质量比9;产物中未形成结晶性氯化锌,且锌粉被氧化成ZnO;行星球磨比搅拌球磨对PVC的脱氯效果好,球磨时间超过3h,PVC的脱氯率可接近100%。 相似文献
845.
研究泉水氢氧稳定同位素时空变化特征,探究泉水的补给来源,对水资源管理及旅游业可持续发展具有重要指导意义。以百脉泉泉群为研究区,通过分析降水及泉水中的氢氧稳定同位素特征,获取了本地大气降水线、泉水同位素时空变化特征及蒸发线,并探究了百脉泉泉水的补给来源。结果表明:大气降水中δ2H的波动范围为-151.55‰δ18O—-4.28‰,δ18O的波动范围为-19.93‰δ18O—-0.52‰,δ2H和δ18O在时间上的分布规律相似,均呈现双峰状(“M”型),本地大气降水线(LMWL)为:δ2H=7.58×δ18O+4.17。百脉泉泉水的δ2H的波动范围为-65.23‰δ18O—-37.01‰,δ18O的波动范围为-8.99‰δ18O—-4.04‰。泉水δ2H—δ18O均落在本地大气降水线上或... 相似文献
846.
基因芯片筛选氯化汞对大鼠脑神经毒性差异表达基因 总被引:1,自引:1,他引:0
为了筛选汞神经毒性差异表达基因和探讨汞神经毒性分子机制,采用基因芯片技术,研究了大鼠皮下注射0.5mg/kg的HgCl2 1h后脑中基因表达的变化.结果表明,基因表达谱中差异表达基因共有742条,上调基因562条,下调基因180条.生物信息学分析表明,差异表达基因中有免疫应答及解毒作用相关基因、遗传信息传递与表达相关基因、细胞信号传导基因、神经传导基因、细胞增殖与分化基因、细胞调亡等多种基因.分析结果提示这些基因的差异表达可能与汞神经毒性有关.利用基因芯片技术筛选相关基因,为深入阐明汞神经毒性的作用机制提供了新思路. 相似文献
847.
848.
Kinetics study on photochemical oxidation of polyacrylamide by ozone combined with hydrogen peroxide and ultraviolet radiation 总被引:1,自引:0,他引:1
An investigation on the process of ozone combined with hydrogen peroxide and ultraviolet radiation has been carried out in order to establish the kinetics for photochemical oxidation of polyacrylamide (PAM) in aqueous solution. Effects of operating parameters, including initial PAM concentration, dosages of ozone and hydrogen peroxide, UV radiation and pH value on the photochemical oxidation of PAM, have been studied. There was an increase in photochemical oxidation rate of PAM with increasing of dosages of 03, H2O2 and ultraviolet radiation. Upon increasing of the initial PAM concentration, the photochemical oxidation rate of PAM decreased. Slight effect of pH value on the photochemical oxidation rate of PAM was observed in the experiments. The kinetics equation for the photochemical oxidation of PAM by the system has been established. 相似文献
849.
A Study of Sorptive Loss Patterns for Reduced Sulfur Compounds in the Use of the Bag Sampling Method
Kim KH 《Environmental monitoring and assessment》2006,123(1-3):259-269
In this work, the basic properties of the bag sampling method were examined and characterized in terms of recovery rate with respect to four reduced sulfur compounds (RSC) including H2S, CH3SH, DMS, and DMDS. For this comparative study, two types of calibration approaches were performed to evaluate the relative RSC loss due to bag sampling. As a reference calibration tool, a syringe dilution (SD) method was applied. The working standards prepared by diluting the primary standard in a gas-tight syringe (as a mixing chamber) were injected to the GC/PFPD through a loop-injection system to yield a background calibration information. In contrast, the target calibration was performed based on a bag dilution (BD) method. To this end, working standards for multiple calibration points were prepared by two different bag types (Tedlar bag (TB) and polyester bag (PB)). These standards were then drawn by the same syringe and injected into the GC/PFPD via loop. On the basis of these comparative analyses, both absolute and relative differences in RSC recovery rates (RR) were evaluated (e.g., comparison of wall-loss effect). The results indicate that TB has a mean RR of 87% for the four RSC with their values ranging from 82 (CH3SH) to 91% (DMDS). On the other hand, the results of PB generally exhibited slightly reduced RR with their mean values of 77% (range: 73% of H2S to 83% of DMS). The results of this study generally suggest that the losses of RSC samples, while inevitable with the bag sampling method, exhibit certain patterns between different RSCs and between different grab sampling materials. 相似文献
850.
Kim KH Choi YJ Oh SI Sa JH Jeon EC Koo YS 《Environmental monitoring and assessment》2006,121(1-3):341-352
In order to explore the environmental behavior of reduced sulfur compounds (RSC) as malodorous components emitted from diverse source processes, the distribution characteristics of four sulfur (S) compounds - hydrogen sulfide (H2S), methyl mercaptan (CH3SH), dimethyl sulfide (DMS: (CH3)2S), and dimethyl disulfide (DMDS: (CH3)2S2) – were investigated in a municipal landfill area. In the course of this study, their ambient concentration levels were measured during two time periods from 13 individual spots selected as a function of distance from the center of the landfill site. The results generally indicated the absolute dominance of H2S over the other S compounds investigated (up to 5 km radius) such that their mean values were found as 1415 (H2S), 148 (DMS), 20.6 (CH3SH), and 14.4 ppt (DMDS). When our data were compared in terms of either varying distance from the source or relationship with meteorological conditions, the H2S data sets were most evident to reflect the potential effects of strong source processes in the landfill environment, relative to other S gases (or to volatile organic compounds measured concurrently). The results of this study further indicated the relatively good correspondence between the measured H2S concentration level and humans' intuitive sensory of odor and nuisance. 相似文献